The sealing bellows of ball-and-socket joints of this type has a first edge area, which is fastened to the housing. A second edge area of the sealing bellows is connected to a thrust ring fixed on the pivot section of the ball pivot via a sliding connection. Such a ball-and-socket joint for motor vehicles is shown, e.g., in CH 465 971. While the first edge area of the sealing bellows is fastened to the housing of the ball-and-socket joint by at least one tensioning ring, the second edge area has a sliding connection. This sliding connection is necessary in the prior-art design especially to make possible a relative movement between the sealing bellows and the ball pivot during rotary movements of the ball pivot around its longitudinal axis. Without such a mobility, the sealing bellows, which usually consists of rubber, would be unacceptably stressed and wear prematurely, because tensile loads may have a damaging effect on rubber. The service life of such a ball-and-socket joint would be consequently reduced.
Since ball-and-socket joints for wheel suspensions in motor vehicles are frequently arranged in the area near the wheel, as is the case in support joints or sliding joints, they are extremely stressed by, e.g., oils, greases, dirt, splash water and corrosive media, such as salt solutions.
Moreover, high thermal load is to be taken into account in case of arrangement in the vicinity of the brake disk. The brake disk is intensely heated during travel and it thus radiates heat, which represents an extreme stress for the components of the joint. It is therefore generally known that protective covers are provided as heat protection shields, which protect the sensitive components of the ball-and-socket joint from the heat radiation of motor vehicle components located in their vicinity. At the same time, these protective covers can also keep splash water away from the ball-and-socket joints at least to a limited extent. As was already mentioned in the introduction, it is necessary to provide thrust rings for one of the edges of the sealing bellows to compensate the rotary movements of the ball pivot. However, there is an additional risk potential for the components of the joint in case of the use of thrust rings, because the penetration of moisture or corrosive media under these thrust rings, e.g., by creeping, could lead to the appearance of corrosion phenomena, especially in the area of the thrust rings of such ball-and-socket joints, which would ultimately lead to a shorter service life of the ball-and-socket joint, because the joint components are worn off more rapidly than desired in the contact area due to the resulting corrosion, and it would no longer be possible to prevent moisture and contaminants from penetrating into the sensitive components of the joint inside the ball-and-socket joint. Additional sealing measures in the contact area between the thrust ring and the ball pivot also fail to rule out this risk altogether. Cleaning with high-pressure washers, in particular, imposes increased requirements on the sealing of affected assembly units.